I'm going to Seoul this summer with a Korean friend. We'll be staying with her family for a few weeks. I've been studying Korean for the last eight months, and can speak, read, and write really basic things (greetings, ordering food and drinks, asking how much something is, etc.). I have a few questions and would be really grateful if native Koreans or English speakers in Seoul could answer them.

1) What are nice gifts to take to my friends' parents?
2) How can I be a good houseguest in Korea?
3) Considering that my Korean is really bad, would it be better to try to order food/services in English? My Korean friends say I'm kind of hard to understand because I put the emphasis on the wrong syllables.
4) Any other tips for not offending the people around me? I'm going to stick out anyway, because I'm a tall redheaded Caucasian, but I really want to be a good guest and tourist.

Thanks!